The Story of Oscar and Louise

I spent a morning going through old saves of my Big Game to find a missing child. He was partially deleted from his family. I found several of the old saves can't travel to Sunlit Tides due to a 'Serious Problem'. Then I tried one where the sims were already in Sunlit Tides so no travelling involved and he was at home with his family. I just grabbed him. I saved him in a Porter file so I can get that mod to handle the doppleganger problem because he isn't completely gone from his current family, his portrait is still there and his Imaginary Friend is in the family inventory and still remembers who its owner is. So I don't want to just add him into the household and fix the family tree. I want Porter to do its magic and turn both versions of him into one sim.